我们新昌县拔茅公社有片中性紫色土(pH为6.8)水稻田,年年出现“倒缩稻”。这种稻出现的时间大体是在插秧后20天左右,其症状,开始是中下部叶片出现褐斑,叶片变小,叶质变脆,严重的叶片中脉出现黄色条斑,衰老后,黄色条斑干枯开裂;再是叶枕距缩短,植株矮化,根系瘦弱细少;最后 We Xinchang County, Mao Mao commune has a neutral purple soil (pH 6.8) paddy fields, year after year, “inverted rice.” The emergence of this rice is generally about 20 days after transplanting, the symptoms begin with brown spots in the middle and lower leaves, the leaves become smaller, the leaves become brittle, and the yellow leaves appear in the midrib of the severe leaves. After aging, the yellow streaks Dry and cracked; and then reduced the distance between the leaf pillow, plant dwarf, thin and thin roots less; finally